RU2503507C2 - Laser plating of thermoplastic powder on plastic materials - Google Patents

Abstract

FIELD: process engineering.

SUBSTANCE: invention relates to application of coating on polymer surface by laser plating particularly in case said plastic and thermoplastic powder are mutually incompatible plastic materials. Method of application of coat 17 of thermoplastic material on substrate 11 made of polymer material. Note here that said thermoplastic material and said polymer material are incompatible. Proposed method comprises the steps that follow. First, said substrate is processed by first plasma discharge 12 or chemically active gas jet produced therefrom to obtain substrate 14 processed by plasma to ensure compatibility of substrate and coating surfaces. Second, powder 16 is applied by laser beam 15 on substrate to make coat on said substrate.

EFFECT: high-quality adhesion.

15 cl, 4 dwg, 2 ex

Description

This invention relates to a method for coating a surface of a polymeric material by laser cladding of a thermoplastic powder on said surface. In particular, if said plastic material and said thermoplastic powder are mutually incompatible plastics.

Laser cladding is a well-known technology for applying metal-based coatings to metal substrates. This technology is used to carry out repairs and / or to increase the corrosion resistance and wear resistance of the component. This process can also be used for applying polymer coatings, for example, as set forth in patent application WO 2007/009197. Briefly, a coating of a thermoplastic material can be applied to a substrate by heating the substrate, in particular by laser radiation (for example, passing a laser beam through the substrate) and simultaneously supplying the powder from said thermoplastic material to the heated substrate. As a result of the absorption of part of the energy of the laser radiation, the applied thermoplastic powder melts and thereby forms a coating. This coating can be sealed by additional heating, in particular by exposing the coating (coated surface) to laser radiation (for example, by re-passing the laser beam over the coating of the substrate).

However, if the substrate and the powder are both made of incompatible plastics, then the applied coating will exhibit poor adhesion to the substrate. Such coatings are not recommended for practical use.

To ensure good adhesion, the materials of the substrate and coatings at the contact area must mutually penetrate each other to ensure adhesion of polymer chains of various materials. However, there are plastic materials that do not provide mutual penetration or provide insufficient mutual penetration during cladding, which leads to very poor adhesion or lack of adhesion. Such materials are incompatible plastic materials or incompatible plastics.

Incompatible plastics refer to plastics that exhibit neither chemical nor physical mutual affinity for adhesion and / or mutual penetration. Incompatible plastics can be dissimilar plastics (plastics with different chemical structures). However, not all dissimilar plastics are incompatible. Incompatibility is possible between polymers with large differences in melting point temperatures or glass transition temperatures, or between amorphous or semi-crystalline polymers.

Accordingly, there is a need in the art for an improved laser cladding method that provides or improves the adhesion or adhesion of the thermoplastic coating to a substrate of a polymeric material, which eliminates the disadvantages of the prior art. In particular, it is an object of the present invention to provide similar methods in which said polymer substrate and thermoplastic coating are initially mutually incompatible materials for adhesion and / or mutual penetration and which, nevertheless, provide good adhesion and / or adhesion.

The purpose of this invention is to provide laser cladding methods in which the adhesion strength exceeds the results obtained in the art.

The objectives of this invention are achieved by creating methods for coating a thermoplastic material on a substrate made of a polymeric material, as set forth in the attached claims.

In accordance with a first aspect of the present invention, there is provided a method for coating a thermoplastic material on a substrate made of a polymeric material, wherein said thermoplastic material and said polymeric material are incompatible, comprising the following steps. Firstly, the substrate is treated with a first plasma discharge or with a stream of reactive gas obtained from it to obtain a plasma-treated substrate. This substrate is treated at least at its surface, said surface being a contact surface with a coating. Secondly, a laser beam passes along the line (along the treated surface) on said plasma-treated substrate, heating this plasma-treated substrate. Thirdly, the powder from the specified thermoplastic material is fed to the specified line, forming a coating on the plasma-treated substrate. The steps of this invention can be performed simultaneously.

In accordance with a second aspect of the present invention, there is provided a method for coating a thermoplastic material on a substrate of a polymeric material, wherein said thermoplastic material and said polymeric material are incompatible, comprising the following steps. Firstly, a powder of said thermoplastic material is treated with a second plasma discharge or a stream of reactive gas obtained from it, to obtain a plasma-treated powder. Secondly, a laser beam passes along a line on the substrate, heating the substrate. Thirdly, the specified plasma-treated powder is fed to the specified line, forming a coating on the substrate. The steps of this invention can be performed simultaneously.

The steps of passing a laser beam through a substrate and supplying powder to form a coating, as defined in the above aspects, relate to coating by laser cladding.

In accordance with another aspect of the present invention, the methods of the first and second aspects are combined.

The methods of this invention may include the selection of a plasma-forming gas so as to ensure compatibility in the area of contact between the substrate and the coating. Accordingly, the plasma-forming gas is preferably selected for the first plasma discharge so as to obtain a chemical group in the surface layer of the substrate that is compatible with the thermoplastic material. The plasma forming gas is preferably selected for the second plasma discharge so as to obtain a chemical group in the surface layer of the thermoplastic material that is compatible with the polymer material of the substrate.

Preferably, the first plasma discharge is formed with a plasma-forming gas selected from the group consisting of air, N ₂ , O ₂ , CO ₂ , H ₂ , N ₂ O, He, Ar, and mixtures thereof. The second plasma discharge is preferably formed with a plasma-forming gas selected from the same group.

Preferably, at the stage of processing the substrate and / or at the stage of processing the powder, the treated surface of the material to be treated is heated at least temporarily, at least to a glass transition temperature, preferably at least to a melting point.

The methods of this invention may advantageously include the step of introducing the first precursor into the first plasma discharge or into the stream of reactive gas obtained from it prior to the processing step.

The methods of this invention may advantageously include the step of introducing the second precursor into the second plasma discharge or into the stream of reactive gas obtained from it prior to the processing step.

Preferably, the first and second precursors are the same.

The first precursor and / or second precursor can be selected so as to ensure compatibility at the contact area of the substrate and the coating. Accordingly, the first precursor is preferably selected so as to obtain a chemical group in the surface layer of the substrate that is compatible with the thermoplastic material. The second precursor is preferably selected so as to obtain a chemical group in the surface layer of the thermoplastic material that is compatible with the polymer material of the substrate.

The first and / or second precursor is preferably allylamine. Alternatively, the precursor is preferably hydroxyl ethyl acrylate. Alternatively, the precursor may be acrylic acid.

The first and / or second precursor is preferably methane. Alternatively, the precursor may be propane. Alternatively, the precursor may be ethylene. Alternatively, the precursor may be acetylene.

The first and / or second precursor may be water. Alternatively, it may be aminopropyltritoxylan.

Preferably, in the processing step, a chemical group is created at least on the material to be processed (more preferably also in said material).

Said chemical group is preferably selected from an amino group and an amido group, more preferably also from an imide group.

The specified chemical group is preferably selected from the group consisting of a carboxyl group, a hydroxyl group and an amido group, and more preferably a hydroxyl group.

The specified chemical group is preferably selected from the group consisting of a carboxyl group, an amino group, a hydroxyl group, an amido group, an imide group, a nitrile group, diimides, isocyanides, carbon dioxide, carbonyl, peroxide and hydroperoxide groups, imines, azides, groups from ethers and esters .

Said chemical group is preferably a siloxane group or a halogen group.

Preferably, at the processing step, the surface layer (either of the substrate, or powder particles, or both) is exposed to plasma with a thickness in the range of 1 Å-1000 nm, preferably in the range of 3 Å-500 nm, preferably in the range of 5 Å-300 nm

Preferably, the methods of this invention further include the step of passing the laser beam along a line on the coating (to seal the coating).

Preferably, said polymeric material (substrate) is a thermoplastic material.

Preferably, said polymeric material (substrate) is a thermosetting material.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 (A-D) illustrate the steps of a method in accordance with an embodiment of the present invention. Figa represents the stage in which the substrate material is treated with plasma using a plasma jet. 1B shows a plasma-treated substrate material. 1C shows the step of coating a plasma-treated substrate with a thermoplastic powder by laser cladding. On Fig presents a finished coated substrate.

DETAILED DESCRIPTION OF THE INVENTION

The following is a detailed description of the present invention with reference to the accompanying drawings, it is assumed that they limit the scope of legal protection of this invention.

It should be noted that the term “includes” does not necessarily imply a limitation to the elements listed below and does not exclude other elements and steps.

Aspects of the present invention relate to methods of coating a thermoplastic material on a substrate of a polymeric material by laser cladding. The thermoplastic material is in the form of a powder, as described above. The substrate, in particular, is a plastic material. The methods of this invention are particularly preferred for cases where the coating material and the substrate material are incompatible.

Used in the description of this invention, the terms "plastics", "plastic materials" and "polymeric materials" refer to the same materials and therefore are used interchangeably.

Incompatible plastics refer to plastics that have neither chemical nor physical mutual affinity to provide adhesion and / or mutual penetration. Accordingly, during the coating (laser cladding) no adhesions and / or mutual penetrations are formed or only very weak adhesions and / or mutual penetrations are formed, while the adhesion of the coating and the substrate is insufficient for practical use. Most dissimilar plastics are incompatible.

In accordance with this invention, at least one material (or substrate material, or powder material, or even both materials) is treated, at least at their surface, with plasma, prior to the coating step.

The influence of plasma is chosen so that it mainly provides the formation of a functional surface layer formed by / on a given surface. Accordingly, mainly chemical functional groups are deposited or accrued predominantly on the surface of the polymeric material and possibly deep into the material.

The wording “functional surface layer” or “functional zone” refers to the surface area treated by the plasma, and possibly to the underlying depth, which undergoes the specified plasma treatment, i.e. it refers to the volume or surface layer.

The functional surface layer mainly contains functional groups. Functional groups relate to chemical groups present in the functional zone that are formed during plasma treatment of the specified zone, which improve and / or provide chemical and / or physical affinity for adhesion to one or more specified plastic materials. These functional groups can be performed by means of a plasma-forming gas and / or by appropriate precursors added to this gas, as described below.

Accordingly, a functional surface layer is provided that surprisingly improves the compatibility of materials during the laser cladding process.

Therefore, the choice of plasma treatment can provide strong adhesion of the laser-clad coating, due to the plasma-treated surface layer, which is compatible with other polymeric materials.

The substrate polymer material is preferably a thermoplastic material. However, it was unexpectedly found that this invention also creates the possibility for laser cladding on a thermosetting substrate material.

Either a powder of a thermoplastic material, or a plastic material of a substrate, or both of them can be plasma treated to create a functional surface layer.

Turning to FIG. 1A, the methods of this invention are illustrated, including the step of generating plasma. This plasma may be a plasma discharge. Alternatively, it may be a plasma afterglow (plasma jet).

The plasma is formed by gas 13, for example N ₂ , air, O ₂ , CO ₂ , N ₂ O, He, Ar and mixtures thereof. Most often they use air and nitrogen. Plasma can be created by methods known in the art, for example, barrier discharge of a dielectric, radio frequency (RF), microwave glow discharge, or pulse discharge. In particular, a plasma jet device 12 can be used. Alternatively, a plasma discharge device may be used.

The plasma-forming gas can be selected depending on the polymeric material (thermoplastic powder material and / or the polymeric material of the substrate), so that the processing of the polymeric material by the plasma formed by the specified gas provides a (functional) surface layer that is compatible with another polymeric material, for example, due to the formation of chemical (functional) groups. Accordingly, a plasma-forming gas can create functional (chemical) groups.

This plasma is preferably plasma at atmospheric pressure. Depending on the application, for the formation of a plasma (discharge), instead of atmospheric pressure, an intermediate pressure (0.1-1 bar) may be preferred.

A precursor, or a chemically active gas (plasma afterglow) resulting from it, can be introduced into a plasma discharge to create a functional surface layer. This precursor can be added as a gas or aerosol, which is activated by plasma energy. A precursor can advantageously be added to create functional (chemical) groups.

A precursor is a chemical compound or molecules comprising predominantly one or more selected functional (or chemical) groups to improve (surface) compatibility of polymeric materials. Alternatively, the reaction of the precursor with the plasma and / or with the polymer material under the influence of the plasma can lead to the formation of such functional (chemical) groups. Functional (chemical) groups may be present on / near the surface of the polymer material subjected to plasma treatment, and possibly below the surface, respectively, with penetration into the polymer material.

Depending on the combination of the polymer material and the plasma, the use of a precursor may or may not be required to form predetermined functional groups providing improved compatibility.

The specified functional chemical group (s) that improves or ensures compatibility at the contact area of the coating and the substrate (or between the surfaces of the substrate and the powder material from a polymer material) can be selected from a non-exhaustive list of groups: carboxyl group, amino group, hydroxyl group, amido group, group imide, imine, nitrile, carbonyl, isocyanide, azide, peroxide, hydroperoxide, ether, diimide, carbonate and esters. The chemical group may be a group containing halogens, alternatively it may be a group of siloxanes (e.g. silicones).

It should be noted that for a given combination of plastic materials, various functional groups can provide the same improvement in adhesion properties. Accordingly, to achieve the same result in the methods of this invention, for a given combination of thermoplastic powder material and polymer substrate material, it is possible to use various plasma treatments.

Precursors, for example, allylamine, hydroxyl ethyl acrylate and acrylic acid, can provide specific chemical groups. Generally, when using a precursor from allylamine, precipitation of amido groups and / or amino groups is possible. Acrylic acid precursors can precipitate hydroxyl, carboxyl groups and / or amido groups. With precursors from hydroxyl ethyl acrylate, precipitation of hydroxyl groups can be obtained.

In many cases, hybrid organic / inorganic precursors can be used to ensure compatibility. For example, a precursor of aminopropyltritoxysilane in a plasma-forming gas provides amino groups on the surface of the plasma-treated material.

The plasma gas itself can provide functional groups without the need for precursors. Typically, nitrogen gas may provide functional groups such as amido groups, amino groups, and modified amine groups. Typically, the addition of some hydrogen or N ₂ O may alter the relative content of the above functional groups. The use of oxygen as a plasma-forming gas usually provides functional groups such as a hydroxyl group, groups containing carboxylic acid, peroxide, ketone and aldehydes.

For example, when performing a functional surface layer containing an amino group, an imide group, or an amido group on a substrate of a polymeric material, a laser clad coating of polyamide (PA) can be coated onto said substrate. Similar groups can be performed by treating the substrate with plasma formed by nitrogen, or plasma formed by a mixture of nitrogen and CO ₂ , H ₂ or N ₂ O. To achieve a similar result, the substrate of the polymeric material can be treated with a plasma-forming gas into which one or more the following precursors: organic chemicals with amino groups (for example, allylamine), with amido groups or an organic precursor for example methane, propane, ethylene or acetylene. In this way, compatibility with amido groups in powder from PA can be obtained.

In another example, when performing a surface layer containing amido groups on a substrate of a polymeric material, a polyurethane (PU) coating by laser cladding can be applied to said substrate. The amido group can be introduced by treating the substrate with plasma formed by air or CO ₂ . To achieve a similar result, the substrate of the polymeric material can also be treated with a plasma gas into which one or more of the following precursors are introduced: an organic chemical reagent with amino groups, with amido groups, with imide groups, hydroxyl groups (water, alcohols, acids, hydroxyl ethyl acrylate, and t etc.), with ester groups, or with ester groups, or an organic precursor, for example methane, propane, ethylene or acetylene. These groups have chemical and physical affinity for PU powder.

For laser cladding of poly (methyl methacrylate) (PMMA) coatings, acrylic groups can be introduced into the functional surface layer on a substrate of a polymer material using an organic precursor containing acrylic groups (e.g. acrylic acid) to ensure compatibility with the acrylic groups of the PMMA material .

As evident from the foregoing, this invention involves the use of any plasma treatment with or without precursors of any type that improves the compatibility of any combination of polymeric materials used in laser cladding. Therefore, the present invention is not limited to either a specific plasma gas or the specific precursors used for plasma treatment.

In the next step, and in accordance with FIG. 1, the substrate 11 to be coated and / or the powder forming the coating is treated with a plasma or a stream of reactive gas obtained from it (plasma afterglow). Methods of plasma processing of polymers are well known in the art and are described in the literature, for example, in Plasma Physics and Engineering by Alexander Fridman and Lawrence A. Kennedy, published by Routledge, USA, in April 2004 (ISBN: 978-1-56032-848-3).

The substrate and / or powder is exposed to a plasma discharge or plasma afterglow for a predetermined period of time. Additionally, a predetermined relative velocity between the acting plasma, or afterglow, and the surface (for example, the speed of a plasma torch relative to the surface) can be selected. Processing time (contact), depending on the application, can be 1 ms - 10 minutes. Particularly preferred processing speeds are in the range of 0.00015-1000 m / min.

Plasma powder treatment is known in the art (Martin Karches, Philipp Rudolf von Rohr, "Microwave plasma characteristics of a circulating fluidizer bed-plasma reactor for coating of powders", Surface and Coating Technology, Volumes 142-144, July 2001, Pages 28-33).

Both the substrate and the powder may be subjected to plasma discharge and / or plasma afterglow. The plasma forming gas may be different or the same for the two materials. For each material, the precursor may not be used; different precursors or the same precursor may be used. In addition, a combination of different precursors can be introduced into the same plasma discharge and / or afterglow of the plasma.

During the plasma treatment, the material to be treated can be heated to an appropriate temperature, in particular when it is required that the plasma-treated zone (the surface layer to be treated) extends into the depth of the material. Preferably, at least the glass transition temperature is achieved during the plasma treatment, and more preferably at least the melting temperature of the polymer material. Alternatively, the treated surface is heated to a temperature that is lower than the glass transition temperature of the processed polymer material.

Heating or high temperature can improve the mobility of polymer chains, which, in turn, improves the formation (buildup) of functional groups, in particular, in the depth of the material.

As a result, an activated volume with a surface (i.e., a surface layer) can be obtained that remains activated even after cooling. Depending on the type of plasma treatment, the treated plastics can last for seconds, hours, days, months or even years without a significant deterioration of the functional area and, accordingly, remain activated during this period. The indicated period depends on storage conditions.

As a result of plasma treatment (with or without a precursor), a surface layer 14 (or a functional zone) is formed, which may contain one or more functional (chemical) groups, as indicated above. Such a surface layer (or functional area) is preferably not limited only to the surface area, but extends into the depth of the plastic material. Similar functional groups can be extended onto polymer chains at the surface of the polymer material to be treated.

The thickness of the (functional) surface layer varies in the range of 1 Å (angstrom) to 1000 nm, preferably in the range of 3 Å-500 nm, preferably in the range of 5 Å-300 nm.

After plasma treatment, laser cladding may be performed in a manner known in the art. Firstly, on a substrate that can be treated with plasma, a laser beam 15 passes, at its surface, possibly treated with plasma. A thermoplastic powder that can be plasma treated is injected using the powder supplying means 16, possibly at the site of exposure to the laser beam, as shown in FIG. 1C. The energy of laser radiation can be absorbed by a substrate, powder, or both, while the energy of laser radiation is converted into heat. It is possible to use laser beam patterns known in the art. The powder can be melted as a result of direct absorption of laser radiation energy, either indirectly due to contact with a heated substrate, or by using both methods. This heating causes the powder to melt and distribute over the substrate to form a coating 17.

Alternatively, a second pass of the laser beam can be made along the coated substrate to densify the coating in order to melt all the powder particles and reduce the porosity between the particles. The specified additional passage can be performed with the same laser beam 15.

In accordance with this invention, the plasma treatment ensures the compatibility of initially incompatible materials, so that after laser cladding and after cooling between these materials (between the substrate and the coating), strong adhesion is formed. The compatibility zone may unexpectedly spread beyond the surface layer (s) 14 formed by the plasma.

Example 1. Laser cladding of a polyamide coating on butadiene-acrylonitrile rubber (BNK).

Prior to laser cladding, substrate activation is performed using a Plasma-Spot® unit (VITO, Belgium) operating at atmospheric pressure. The selected gas mixture is ionized in the plasma zone and blown out of the burner. In this way, an afterglow of the plasma is created, which is suitable for processing substrate materials of various types and various geometric shapes.

To create an active plasma afterglow, a mixture of nitrogen and carbon dioxide was ionized in a Plasma-Spot® installation. A power supply with a rectifier with a direct current at the output was used, which was converted into an alternating current signal with a frequency of 75 kHz. High voltage was obtained using a transformer. Power dissipation was set equal to 10 W / cm ² , and the total flow was maintained by mass flow controllers at the level of 80 standard. l / min with a ratio of N ₂ / CO ₂ -72/8 standard. l / min

The surface of the BNK substrate was treated at a distance of 4 mm from the Plasma-Spot® installation. The processing of a flat sample was carried out at a speed of 8.2 s per cm ² .

The laser cladding tests were carried out on a 150 W continuous diode laser (with a wavelength of 940 nm). During the first stage, the BNK substrate subjected to plasma processing at atmospheric pressure was heated by passing a laser beam over its surface. At the same time, a powder of polyamide was blown into a laser beam on a heated surface at a flow rate of 1.5 g / min by means of argon as a carrier at a flow rate of 10 l / min. This process was regulated using a non-contact optical pyrometer, which continuously measured the surface temperature of the laser-heated zone. To provide feedback control, the signal of the actual surface temperature was used as a control variable, while the nominal temperature was used as a control variable. In accordance with the mechanism of action of the PID controller, both signals were compared, and a new value of the output signal was calculated based on the difference of both values. The laser power was preferably selected based on the output power of the regulator, since it is the most flexible value (compared to the speed of the laser relative to the substrate).

As a result of contact with the substrate heated by the laser, the powder from the polymer material partially melted. Laser movement and powder supply were provided at a speed of 2000 mm / min with a technological transition width of 1 mm. For a powder of polyamide, the substrate was heated by a laser to a temperature in the range of 180-400 ° C, and the limits were determined based on the melting temperature of the powder and the temperature at which the deterioration of the quality of the powder occurs. You can get a rough layer with a thickness of 100-400 microns. To re-melt the specified upper layer and reduce surface roughness and porosity, the step of re-passage with a laser is performed without adding powder. The re-melting step is usually performed at a speed of 750 mm / min and a temperature of 150-350 ° C.

The peeling test showed better adhesion of the molten polyamide layer to the BNK substrate when performing plasma treatment of the substrate at atmospheric pressure. The average tear strength increased from 30 N / mm to 350 N / mm.

Example 2. Laser cladding of a polyamide (PA) coating on a substrate of polypropylene (PP).

Afterglow of plasma at atmospheric pressure was obtained by means of a plasma jet providing apparatus (Plasma Jet®DC, Raantec, Germany). Air was used as a plasma-forming gas. The air flow was maintained at a flow rate of about 30 l / min (with adjustable pressure). The tests were carried out without the use of precursors and at a power of 290 watts. Such a plasma provided polar chemical groups on the surface of PP that are compatible with the amide groups of the polyamide.

The substrate of PP was located on the coordinate table and processed by afterglow of the plasma at atmospheric pressure. PP substrate during processing was kept at a distance of 10 mm from the specified installation. The processing speed was 5 m / min.

After this plasma treatment at atmospheric pressure, laser cladding tests were carried out under conditions similar to those of Example 1. In this case, the best adhesion of the PA coating to the PP substrate was obtained.

Claims (15)

1. The method of coating (17) of a thermoplastic material on a substrate (11) made of a polymeric material, wherein said thermoplastic material and said polymeric material are incompatible, comprising the steps of:
treating the substrate with a first plasma discharge (12) or a stream of reactive gas obtained from it, obtaining a plasma-treated substrate (14) and forming one or more chemical groups exhibiting chemical or physical affinity for bonding with the thermoplastic material on this plasma-treated substrate;
laser beam (15) passes along a line on said plasma-treated substrate, heating the plasma-treated substrate; and
powder (16) from said thermoplastic material is supplied to said line, forming a coating (17) on a plasma-treated substrate. 2. A method of coating a thermoplastic material on a substrate made of a polymeric material, wherein said thermoplastic material and said polymeric material are incompatible, comprising the steps of:
treating the powder from said thermoplastic material with a second plasma discharge or a stream of reactive gas obtained from it, obtaining a plasma-treated powder and forming one or more chemical groups exhibiting chemical or physical affinity for bonding with the thermoplastic material on this plasma-treated powder;
passing through a line of a laser beam on a substrate by heating the substrate; and
the specified plasma-treated powder is fed to the specified line, forming a coating on the substrate. 3. The method according to claim 1, characterized in that the processing of the powder is performed in accordance with claim 2. 4. The method according to any one of claim 1 or 2, characterized in that the first plasma discharge and / or second plasma discharge is formed with a plasma-forming gas selected from the group consisting of air, N ₂ , O ₂ , CO ₂ , H ₂ , N ₂ O, He, Ar and mixtures thereof. 5. The method according to claim 1, comprising the step of introducing the first precursor into the first plasma discharge, or into a stream of reactive gas obtained from it, prior to the processing step. 6. The method according to claim 2, comprising the step of introducing a second precursor into the second plasma discharge, or into a stream of reactive gas obtained from it, prior to the processing step. 7. The method according to any one of claim 5 or 6, characterized in that the first and second precursors are selected from the group consisting of: allylamine, hydroxyl ethyl acrylate, acrylic acid, methane, propane, ethylene, acetylene, aminopropyltritoxylan and water. 8. The method according to any one of claims 1, 2, 5 or 6, characterized in that the chemical group is selected from the group consisting of: carboxyl group, amino group, hydroxyl group, amido group, imido group, nitrile group, diimide, isocyanide, carbonate, carbonyl, peroxide, hydroperoxide, imine, azide, ether, esters, siloxane and halogen. 9. The method according to any one of claims 1, 2, 5 or 6, characterized in that at the stage of processing the surface layer is exposed to plasma with a thickness in the range of 1 Å-1000 nm, preferably in the range of 3 Å-500 nm, preferably in the range 5 Å-300 nm. 10. The method according to any one of claims 1, 2, 5 or 6, further comprising the step of passing the laser beam along a line on the coating. 11. The method according to any one of claims 1, 2, 5 or 6, characterized in that said polymer material is a thermoplastic material. 12. The method according to any one of claims 1, 2, 5 or 6, characterized in that said polymer material is a thermosetting material. 13. The method according to any one of claims 1, 2, 5 or 6, characterized in that at the stage of processing the substrate and / or the stage of processing the powder, the treated surface of the processed material is heated, at least temporarily, at least to a glass transition temperature, preferably at least to a melting point. 14. The method according to claim 3, comprising the step of introducing the first precursor into the first plasma discharge, or into the stream of reactive gas obtained from it, before the step of processing and introducing the second precursor into the second plasma discharge, or into the stream of reactive gas obtained from it, to the processing stage. 15. The method according to 14, characterized in that the first and second precursors are the same.